The present invention relates to preventing interference between wireless devices and protected sites.
The advent of satellite communication systems has resulted in potential conflicts between emissions from the satellite telephones and other systems. A radio astronomy site (RAS) is one example of a site requiring protection. Equipment at radio astronomy sites take measurements of radio waves over an interval of time, known as the integration interval. During the integration intervals, signals emitted by nearby satellite telephones may be detected by the RAS equipment. This can result in errors in the measurements made at these sites. Other sensitive sites that satellite telephone transmissions might interfere with include airports where sensitive satellite navigation equipment may be used.
An approach has been developed to avoid such interference between satellite telephones and other systems. This approach includes transmission of a beacon signal from the site requiring protection. For example, the beacon signal is transmitted from the RAS during the integration interval of the RAS equipment. When a satellite telephone detects the beacon signal, it shuts down. This prevents emissions from the satellite telephone interfering with the protected site. The beacon signal is designed such that its transmit power, antenna pattern, shielding and frequency of operation produce beacon emissions that do not have a detrimental impact on the measurements.
Although this system prevents interference, it is desirable to provide a more intelligent beacon system.
A wireless device selectively operates near a protected site. The wireless device responds to a detected beacon signal. Interference parameters are used to control operation of the wireless device to avoid interference with equipment at the protected site. The operation is selectively altered depending upon the inference parameters ascertained whereby the wireless device does not necessarily have to be disabled.
A method of operating a control system to intelligently control a wireless device near a beacon system is also disclosed.
A wireless device selectively operating near a protected site is also set forth. A control system for wireless devices operating near a protected site is disclosed.